Based on your question I found the issue when I went into the blueprint view. The line item Growth % was set to weeks, though I'm not sure why, when I set the module to months after creation. Does changing a module timescale not change the line items within it?
The overall calendar IS set to weeks. I was aware of this, but since there was no instruction to change that, I left it. The issue came down to the line item, which I guess I assumed would take the module's setting, not the calendar's.